JSON vs YAML: Choosing the Right Format

JSON

Strict superset of JavaScript object syntax. Every value must be quoted strings, numbers, booleans, null, arrays, or objects. No comments.

Strengths: universal support, fast parsing, unambiguous, great for APIs.

YAML

A superset of JSON with human-friendly syntax. Supports comments, multi-line strings, anchors, and aliases.

# YAML supports comments
server:
  host: localhost
  port: 8080
  tags: [api, v2]

Strengths: readable config files, less punctuation noise.

When to Use Each

Use case	Format
REST API responses	JSON
CI/CD config (GitHub Actions, etc.)	YAML
Package manifests	JSON
Kubernetes manifests	YAML
Inter-service messaging	JSON

Gotchas in YAML

• no, yes, on, off parse as booleans in YAML 1.1
• Indentation matters — tabs are not allowed
• Norway problem: country code NO parses as false

Convert between the two instantly with the JSON ↔ YAML Converter.